


Locard's Exchange Principle

by osmia_avosetta



Category: Sherlock (TV)
Genre: Gen, Implied/Referenced Character Death, Pre-Episode: s01e01 A Study in Pink
Language: English
Status: Completed
Published: 2018-01-04
Updated: 2018-01-04
Packaged: 2019-02-28 00:45:48
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 5,459
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/13260063
Author URL: https://archiveofourown.org/users/osmia_avosetta/pseuds/osmia_avosetta
Summary: A meeting, an exchange, and the dominoes fall. A one-shot.





	Locard's Exchange Principle

**Author's Note:**

> Locard’s Exchange Principle states, in (a very condensed) summary, that with contact between two items, there will always be an exchange. This story is set before the events of _A Study in Pink_ , as well as before the Tbilisi fiasco.

The needle hovered precariously over the mole on the target’s neck. 

“Please!”

Pleading did nothing to calm the man who had the target in a headlock, lowering the needle towards the target's skin. 

“You utter piece of  _ filth _ ,” Sherlock Holmes hissed between his teeth. “Defiling the reputations of  _ innocent people?  _ Using  _ government funds  _ to carry out your nefarious acts? You don't deserve to  _ plead _ ,” Sherlock spat. “You don't even deserve to speak.”

“Please! Please!”

Sherlock laughed mirthlessly. “I bet your victims pleaded with you to  _ spare them  _ like you're doing now. A taste of your own medicine, do they call it?”

“I...there are people who can...I'll have you prosecuted...you can't threaten a member of Parliament!”

“ _ Former, _ ” Sherlock hissed. “My brother made sure of that.”

The target went still, possibly in shock. “You're…you're a  _ Holmes _ !” he realised. 

“Yes, good sir,” Sherlock replied dryly, not letting the man go. “You might want to think before you threaten.”

“But  _ your precious brother  _ isn't here now,” the man laughed hysterically, the needle centimeters away from his neck. “I can threaten you all I like!”

Sherlock sighed boredly. This was getting old for him.

“No. You won't,” Sherlock whispered coldly and drove the needle down. 

_ Flump! _

The trafficker and embezzler slumped to the ground as Sherlock jerked the needle out of his neck. 

“You...you,” the target managed to choke out as Sherlock deftly took out a pair of handcuffs and locked him up. The agents who’d been lying in wait were likely to come soon, and the tranquilizer was just about to kick in.

Sherlock sniffed haughtily and turned away, busying himself with putting away his syringe and straightening out his coat as the target groaned in pain from behind him.

He sighed and turned his gaze upward. 

Mycroft had sent him on this mission, presumably to keep him out of major trouble, if only for a short while. Fluffy white clouds skidded past the earth below against a sky of deep blue. The hills were quiet this afternoon, save for the breeze making the leaves of the oaks sway. Nobody seemed to want to venture around this area, and of this Sherlock was quite glad. He pitied anyone who'd unwittingly seen him take down one of the most unsavory characters Mycroft had made him chase and arrest. 

He'd been placed in the historical section of a little American city, situated in a sprawling valley, where the target had presumably gone into hiding after his actions were exposed by the government. The whole area looked like a movie set for some old Wild West film.  _ Boring. _

Sherlock surveyed his surroundings. He’d taken the target out of the town center, lured him to a copse of oaks far away from any commercial or residential buildings, and pretended to be a “customer” who was interested in the target’s line of business. Unfortunately, the target had been wary of Sherlock and had almost run away, but in the end it was Sherlock that was the quicker of the two, forcing the target into a headlock and tranquilizing him. The agents stationed around the copse would come to collect the target and have him extradited back to England.

An easy job.

Almost boring.

He yearned for London: its constant hum of life, far different from the quiet of the town in which he’d been placed. Sure, tourists ambled about in the streets, taking pictures and sampling food, but it was all so  _ unextraordinary.  _ So  _ normal. _

Two of the things Sherlock Holmes disliked most.

In a way, Sherlock had to admit that this was all just a way to keep him off the drugs, to keep him out of the web he'd spun for himself, that first night when he'd picked up the syringe simply because of his curiosity. From there, he'd slowly progressed downwards and downwards until the night he'd almost died and woke up in hospital with a file placed on his lap and Mycroft sitting at his side with a look of frank disappointment pasted on his face. 

From there, Sherlock had gone on countless undercover operations around the world for MI6, all without monetary reward, all alone. 

He didn't mind it: in fact, every manila file that was placed in front of him was an escape, another ticket to another place in the world where he could use his mind, another reprieve from the risk of his mind tearing itself apart due to sheer boredom. 

And now, two years after that first folder...he was here. 

Still alone, but that  _ did not matter.  _

He whirled around to wait for his agents.

Almost as if on cue, several dark-clothed agents dropped from the oaks and warily approached. One agent stepped forward, slipping her Glock into a holster.

“What’s in a name?” she asked him cautiously, her colleagues taking up defensive positions at her side.

“That which we call a rose by any other name would smell as sweet,” Sherlock rattled off. “Yes, yes, I know.”

“Good. Best get it on with,” the agent barked at her colleagues. “Thank you, Mr. Holmes,” she added with a respectful nod towards him. “You have been an asset to this operation.”

The agents were fast, clearing away their prisoner almost as fast as Sherlock had taken him down. Eventually, Sherlock was left alone in an empty copse, having promised the agents that he had a mode of transportation with which to go back to the town area.

And what would tomorrow bring?

No doubt he’d be on a plane back home to his England.

He sighed and turned away, beginning to traipse back down to the little flat his brother had rented for him at the center of the historical section of town.

Suddenly, a female voice spoke out from behind him.

“Hey! Hey, you!”

Sherlock whirled around, guard up. A faint rustle of leaves, and a dark figure dropped neatly onto the ground.

“Who are you? What do you want?” he called out warily, muscles tensing. His heart rate began to accelerate. This was  _ interesting.  _ Perhaps this town wasn’t so ordinary after all...

“To talk, that’s all,” a woman replied from her post underneath an oak. “You can trust me.”

“Come forward if I can trust you,” Sherlock shot back.

“Fine,” the woman responded with an easy shrug and sauntered to Sherlock’s post.  _ British? Strange,  _ he noted, listening intently to her accent. As she walked closer, he took her whole figure in.

The woman standing before him was dressed against the somewhat nippy winter chill in a dark coat, tight-fitting black trousers, and, Sherlock noted with a raised eyebrow, hiking boots. She was slim and rather small, with auburn hair and greenish eyes, a round, rather friendly face, and moderately thick eyebrows.  _ 160 cm, most likely. In her 30s? Not her natural hair color. Only Child. Linguist. Clever. Shortsighted. Guardian. Cat Lover. Romantic. Appendix Scar. Secret Tattoo. Size 12.  _

She stopped a couple of feet from him, pulled a handgun out of a hidden holster, and laid it on the ground. 

“There you go, I'm disarmed now,” she said smoothly, putting her arms up. Sherlock raised his eyebrows as he analyzed the weapon, then looked back up at the woman in front of him. 

“CIA?” he guessed out loud. 

Her face remained impassive. Sherlock was mildly impressed. This woman had been well trained. 

“Alright, never mind,” Sherlock backtracked. Perhaps the subject was a bit not good? “Let’s talk,” he said instead. 

Her face moved from impassive to quite angry, and she advanced without warning. Sherlock’s eyes widened, and he took a couple of frantic steps back - only to collide with a stout tree. The rough bark caught on the fabric of his coat. 

He cursed under his breath. 

“ _ You stole our target, _ ” the small woman snarled angrily, raising a finger to point at him and practically stabbing his chest. The very tip of her finger seemed to quiver furiously as Sherlock stared down at it, arms dangling helplessly at his sides. “You don't know how much we  _ needed  _ this one,” she hissed. “We've been stuck in an attic for months! What’s more, you had to come in with  _ all  _ these agents and -”

_ We? _

“Wait!” Sherlock said, putting up his hands placatingly. The woman paused her wild tirade, mouth half-opened. “ _ We? _ How many of you are there? And why are...why  _ were  _ you watching the same target as me?”

“We needed this target,” she repeated. “If we'd only gotten to him…”

Suddenly, Sherlock heard the woman’s stomach faintly growl.

He pursed his lips, knowing it wouldn't be a good idea to bring it up. She tried valiantly to ignore it, although the pink around her ears told a very different story. 

She leaned down, grabbed up her handgun, and shoved it back into the holster. 

“This isn't the best place to talk,” she said shortly. “We're going to town. I know a good place to eat.”

Sherlock weighed his choices and decided to follow her as she traipsed down the hill, not bothering to check if he was following. 

“And you're picking up the tab,” she shot over her shoulder. 

Sherlock jogged to catch up. 

The woman led him, surprisingly enough, quite close to where Mycroft had put him. From the little booth in the Mexican restaurant, Sherlock could see the room in which he’d spent his nights for the last few weeks. 

American pop music was playing faintly from the speakers, and a quiet hum accompanied the clinking of forks and the cars passing by outside the building. 

Across from him, the woman he'd followed had her hands folded calmly on the tabletop. She was eyeing him carefully, ignoring the glass of water to her left. 

_ Left handed,  _ Sherlock deduced further. 

“You said you wanted to talk,” he said carefully. “Why don't we start with your name?”

She stayed silent. Sherlock sighed.  _ Let's do this the hard way, then.  _

“Fine.” He stretched his hand across the table. The woman eyed it impassively. “Sherlock Holmes.”

“You're not from around here,” she observed, not taking his hand. “British? MI - something, right?”

Receiving a nod from him, she continued. “But not really, right? You're not formally part of them.”

Sherlock cleared his throat awkwardly.

“Special case,” he mumbled.  _ Clever girl.  _ She’d been observant enough to notice he wasn’t formally a member of MI5 (or MI6, for that matter).

The woman, to his surprise, broke into a wry grin and shook his hand across the table.

“Good to meet you, then, Sh…?”

“Sherlock.”

She laughed then, a pleasant little sound. “That's a  _ silly  _ name,  _ Sherlock _ ,” she said, letting go of his hand and folding her hands on the table again. 

“What's yours, then?” Sherlock asked the woman. “You still haven't told me yours.” Despite her apparent ease around him, Sherlock was still a bit wary of this woman. He needed more information, more  _ data _ ...and yet, he somehow knew that she didn’t want to harm him at all. 

The woman smiled impishly and grabbed a plastic-covered menu from the stand at the edge of the table. She placed it flat on the table and tapped a fingernail on the name at the head. 

**_The Rose Café_ **

“Rose?” Sherlock raised an eyebrow. 

The woman pulled a pen out of her coat pocket and pulled a paper napkin out of the container beside the menu stand. She scribbled on the napkin for a few moments, then pushed it towards him and pocketed the pen. 

Sherlock took it and read, forehead creasing. 

_ e _ _ , -amund _

Sherlock slowly put two and two together.  _ Rose, drop the  _ e,  _ add -amund… _

“Rosa -” he started out.

“Shh!” the woman said urgently, putting her finger to her lips. Sherlock caught himself just in time. Perhaps this woman didn't want her name given out and spoken freely. He understood perfectly. 

_ Rosamund.  _ So that was her name. 

_ What's in a name? That which we call a rose / By any other name would smell as sweet.  _

He had to admit that it was a rather nice name. 

“It's a nice name... _ Rosita, _ ” he couldn't help poking at her. After all, she'd called his name  _ silly,  _ couldn't he have a bit of fun with her?

She frowned at him, but Sherlock caught a merry twinkle in her eyes.

“Thanks very much,  _ Shirley, _ ” she poked back.

Despite himself, Sherlock let out a hearty laugh. Across the table, Rosamund did the same, her eyes crinkling up at the edges.

A waiter seemed to spontaneously appear at their table, and Sherlock and Rosamund immediately sobered. 

“Fish tacos?” he asked. 

Sherlock raised a hand lazily, and the waiter set the dish down before him. 

“Then the rice must be for you, ma’am,” the waiter said, setting the bowl before Rosamund. She nodded and smiled up at the waiter. Sherlock found himself smiling along with her. 

“Right, enjoy,” the waiter said briskly before walking away. 

Rosamund sighed in anticipation and dug her spoon in without preamble. Sherlock watched her, deducing.  _ Probably first meal in a while.  _

He tore his gaze away from her and addressed his food: fish wrapped in...tortillas? Sherlock wasn't too well-versed in the food culture of the American southwest. 

He sighed and gingerly peeled the flour wrapping off the pieces of deep-fried fish, laying each one aside with almost epicurean care. It wasn't the tortilla he was here for, after all. And he missed his favourite fish and chip place back in London. 

“You miss England,” Rosamund commented. 

Sherlock slowly looked up at his dinner companion. 

“Don't you, Shirley?” she continued, spoon half-lifted to her mouth. 

Sherlock took a napkin from the dispenser and daintily wiped his hands. He desperately tried to keep himself from laughing at her deliberate butchering of his name. “How did you know?”

“You miss the fast food,” she said in a rather matter-of-fact way, nodding to the fish on his plate. “You miss the chips especially. I didn't think you were the type to enjoy fish and chips. And yet…” She jammed the spoonful of rice into her mouth, leaving the end of her sentence hanging in mid-air. 

Sherlock stared at her for a bit. 

_ Clever, indeed.  _

“You're not English...Rosita,” he observed, tacking on the name.  _ An eye for an eye, and she did call me Shirley again.  _

Rosamund swallowed her bite of food. “Not by birth, no,” she acknowledged. “But I did so love the country.”

“Been there quite a bit, haven't you?”

“Yes, actually,” she admitted. “I'd love for another chance to go back.”

Sherlock didn't know how to reply, so he let an affirmative sniff serve as one. 

They continued to eat in companionable silence for a while, until Sherlock deigned to ask the question that had been on his mind since Rosamund had first spoken to him, but hadn't dared to ask. 

“How many of you are there?” he asked her. 

And suddenly, Rosamund couldn't meet his eyes. 

“Obviously you're not the only one. You specifically said  _ we  _ when you were loudly berating me in the oak copse.”

“Why do you want to know?” Rosamund glared lightly across the table at him. 

Sherlock glued his mouth shut. 

“Fine, then.” Rosamund grabbed a napkin and wiped her mouth with almost as much epicurean care as Sherlock. “There's four of us, Shirley, and we're all crammed in a little room around this area. We used to be CIA, all of us. You were right about that.”

Sherlock nodded and made to grab a napkin to wipe his own hands. Rosamund grabbed a napkin for him and held it out. He accepted it with a nod of polite thanks. 

“But now we're not,” Rosamund said frankly. “We’re freelance now. Someone commissioned us to go after your target a few months ago. We've been in waiting for a month, monitoring his movements. We just didn't expect that someone else would have the same target. And that that someone would make the first move.”

“Oh.” His mouth went dry. Had he prevented a group of people from getting the money they needed to get by? He felt a bit guilty. “I...were you being…”

“Paid? Yes, we were.” Rosamund sounded moderately disappointed. She idly dragged some rice around her plate. “I don't know...I don't know what we're going to do now.”

“If it makes you feel better, I'm not paid either,” Sherlock said carefully. “I'm not even part of MI5  _ or  _ MI6. I'm just doing this on orders from my brother.”

“So he's high up then?”

“He claims he isn't.”

“I'd do the same, if I were him.” 

An awkward silence descended over the pair, broken only by the waiter reappearing by their table.

“Everything good for you both?”

Sherlock practically jumped, much to Rosamund’s general amusement. He could see her carefully hide a little smile. 

“Yes. We are  _ fine, _ ” Sherlock sent a look across the table to Rosamund. “Thank you.”

Rosamund choked out a giggle. 

“Okay then. Let me know if you need anything,” the waiter continued, blissfully unaware, before ambling off. 

The two stared at each other for a moment.

Then Rosamund broke loose and burst into giggles.

Sherlock lost it as well, and began to laugh for the first time in a long while.

* * *

 

They ended up walking down the main street amiably, occasionally crossing it to avoid the hordes of tourists who were ambling about taking photographs.

“It's a nice little town,” Rosamund commented as they wove around a group of tourists chattering in some unfamiliar language.

“Bit uneventful, though.”

“That, too.”

Sherlock had started out walking with his hands behind his back, but now he offered his elbow to Rosamund, who looped her arm through companionably. To any innocent passersby, they looked like two good friends touring the little town and taking in the lights that had been put up for the holidays. 

Rosamund exhaled next to Sherlock. It had grown so cold that one could see their breath in the night air. 

“Do you have anyone back...home? Back in London?” Rosamund asked. “It's okay if you can't tell me.”

“It's fine,” Sherlock shrugged, stepping neatly over a puddle. “But I don't have...anyone at home. Well, my brother, but then again I rarely see him.”

“No girlfriends? Boyfriends?”

Sherlock sniffed. “Nope,” he said, popping the  _ p  _ as he stared up at whatever stars could be seen among the cloud cover. 

“You're  _ alone? _ ” Rosamund asked incredulously, as if she couldn't stand the idea. “As in, totally and completely  _ alone?”  _

“I believe we've already established that point,” Sherlock replied shortly.

They entered a little playground, mercifully empty and still. Music could be heard distantly, and Sherlock thought he heard strings among the singing. For a second, he wildly wished he had his violin. Mycroft had not allowed him to take it on this mission.

“Well, you don't have to be,” Rosamund retorted, sitting down on a swing and setting it into motion with a tap of her foot. “You don't  _ have  _ to be alone.”

“Alone is what I have,” Sherlock said quietly, sitting down on the swing next to her. “Alone protects me.”

“Hey,” Rosamund said, a hint of fierceness entering her voice. “Don’t say that, Sherlock.”

“Well, I can say things if I feel they are true,” Sherlock replied, a bit taken aback by how quickly her demeanor had changed. 

“But it isn't, Shirley. It's not true.” Rosamund turned about in her swing, the chains creaking as she twisted the swing so she was facing him.

She put a hand on his arm. “No one deserves to be alone.  _ No one.  _ I learned that lesson a long time ago, and I don't regret it, ever.”

They stared at each other for a few seconds, Rosamund’s gaze strangely intense, Sherlock’s locked on the hand on his arm.

Rosamund’s gaze followed his to his arm, and her hand attached to it. “Oh. Sorry,” she apologized quickly, removing her hand.

Almost against his will, Sherlock’s hand moved up quickly and caught it. Rosamund instantly clammed up.

“No, Rosamund…” he said quietly. “There really isn’t any need to apologize.”

“I forgot my place,” she returned with a bit of edge in her voice, shoving her hands in her pockets. “You’re a government agent -”

Sherlock was instantly on the defense. “Christ, Rosamund, I’m not -”

She cut him off. “I’m a damn  _ freelance agent  _ -”

Sherlock cut her off in return. “And you actually wanted to talk to me, which nobody ever does -”

Rosamund seemed to have ignored him. “And God knows how much about us you’re going to reveal to your  _ high-up brother _ and put us in jeopardy, because I f...I forgot my place!” She stared at him for a bit, catching her breath. “Wait, what did you say?”

“Nothing. I said nothing,” Sherlock denied stubbornly. God knew he was going to say something stupid and sentimental and  _ begging for companionship or some other crap  _ like  _ that  _ again.

“Fine. But I’ve said too much,” Rosamund said. To Sherlock’s surprise, she let out a humorless laugh. “Where’s your syringe, then?”

For a second Sherlock thought she was referring to the night he had almost died, and he tensed up because  _ how the hell does she know about any of this?  _

“Where’s your syringe, Sherlock? When are you going to tranquilize me and haul me off, yeah? Where’s the battalion of agents waiting to scoop us up and have us tried in some international court of f...law for all the jobs we’ve done?” 

She smiled, but there was no joke in her tone, no teasing. This was a taunt.

This hurt Sherlock.

Hurt...hurt was no stranger to Sherlock Holmes. Redbeard? Redbeard. A collar, a dish. A handful of red fur. A scream over the grass. A scream into the trees. A small hand. A fire.

Screaming.

Screaming. Screaming. Screaming. He was always screaming.

Yes, hurt was an old friend.

Sherlock felt his face turn to stone, and he looked away from Rosamund’s eyes, her hair, her voice.

“Stop, Rosamund,” he said, trying hard to keep his temper down. He could have yelled. Screamed. Shouted at her, pulled back his fist and let it sail like he would have with a drunken idiot annoying him on the street.

Sherlock stared down at his hand, the hand that had been holding Rosamund’s moments earlier, and balled it into a fist. The cold was making it hard for him to clench his fingers together, and he cursed himself for leaving his gloves at the flat. 

He couldn’t do this.

“Stop,” he murmured, but it was more of a mantra than anything else.

The chains creaked from next to him.

Sherlock jerked his head up.

The swing next to him was empty.

A shadow darted across the deserted playground.

Sherlock picked himself up and dashed after it.

He chased after Rosamund across what he felt was at least half the valley, weaving in and out of alleys, dodging cars, apologizing profusely and in more languages than he thought he’d have to use. At one point, he jumped over a dog in a down vest and kept running.

Sometimes, she tried throwing him off, darting into crowds and pretending to stand in lines. Once she even stole a pair of ice skates and attempted to make him lose her in a crowd of people attempting to skate laps around the seasonal ice rink. It was easy to find her then - Sherlock needed only to find the most experienced skater and there she was.

She tossed her skates into the bushes, yanked on her boots, and ran.

Sherlock knew she was armed - she’d pulled out her gun in front of him. But they were in a remarkably public place, and if she pulled out a gun here and fired, there would be more trouble than Sherlock could have bargained for.

However, Sherlock also knew one thing, and he held onto it like a lifeline - Rosamund did not want to kill him. If she did, she had had so many opportunities to kill him that she never took. A shot with a silencer would not be amiss in the wilderness, back in the copse of oaks. She could have even killed him back in the park, pulled out her gun and put a bullet through his head as they sat on the swings. And now, she was staying specifically where it would be least good to pull out a weapon.

No, she did not want to kill him. Just shake him off, and forget this ever happened.

He chased after her anyway. 

There was one more thing he wanted to say.

It took what seemed like forever, a loop through a random Post Office Museum, and a hurried set of apologies to a string ensemble walking along with their instruments, but he finally caught up with Rosamund.

“Christ, Rosamund,” he said, valiantly attempting to catch his breath as he stopped her outside an olive oil tasting shop.

“What do you want?” she spat at him. 

Sherlock put up his hands. “You really like having the last word, do you? Always have to leave the other person before they can get a rebuttal in edgewise?”

Rosamund glared at him.

Sherlock sighed. “Listen,” he said. “I’m not going to say anything to anyone. I already told you, I’m not officially affiliated with anybody. Even if I said anything about your...group, well, it’s highly unlikely they’d believe me anyway.”

Rosamund’s glare softened, but held.

“You said you needed this job?” Sherlock asked. Rosamund hesitated, then nodded.

Sherlock held up a finger,  _ one moment.  _ Then, he stuck his hand, stiff from the cold, into his coat’s inner pocket and fished around. 

In front of him, Rosamund tensed, and her hand drifted to her hip.

Sherlock tried to find what he was looking for. His fingers sensed and knocked away a cork, a mobile charger, and a pen cap before - 

“Here,” Sherlock said finally, holding out the little card towards Rosamund.

Sherlock already knew the contents of the card. Hoping to annoy his brother, he’d swiped it off his desk at the Diogenes Club while in there alone. Mycroft probably knew that he had stolen it, but had never said anything to him. For all intents and purposes the card (and its contents) were probably unimportant to the elder Holmes brother.

But as for Sherlock, he was rather grateful he’d stolen it.

_ Lady Elizabeth Smallwood,  _ the card read across the top in neat letters, and then a phone number underneath. Sherlock didn’t know (and didn’t care) why Lady Smallwood had given Mycroft her phone number, but what he  _ did  _ care about was that she had quite a lot of power.

Perhaps she’d be able to help.

Rosamund wordlessly took the card and read it. Her eyes widened slightly.

“Lady Smallwood?” she asked him. “You  _ know  _ Lady Smallwood?”

“Not me,” Sherlock said. “I told you my brother was high up.”

“I didn’t think  _ this  _ high up,” Rosamund murmured, the glare melting entirely as she re-read the card again. 

“Call the number,” Sherlock said. He wasn’t sure if this was going to work, but maybe he could help Rosamund and her...group find a future. Judging from Rosamund’s abilities, they looked like a well-trained group.

Sherlock knew enough about espionage and handling agents from his brother to know that well-trained agents stuck in boring towns was really a colossal waste.

“Call the number,” Sherlock said, “tell her who you are, tell her what you do, let her know you’re in need of work. Maybe she can help.”

“My God,” Rosamund murmured. She slipped the card deep inside her coat, then looked up at Sherlock skeptically. “You really...this isn’t a trick, is it?”

“No tricks,” Sherlock said sincerely. “That’s really her phone number.”

Rosamund continued to eye him for what felt like forever before finally nodding and drawing her hand out of the coat with a grin. “So…” she put her hands up, palms facing the sky. “That’s all? That’s all you wanted to say?”

“Yes,” Sherlock said, relief filling him. “Yes, that’s all.”

“Well, then,” Rosamund said, with an awful sort of finality to her tone. For a second Sherlock thought she was going to shoot him, but she stuck out a hand. “It’s been a pleasure.”

“Indeed,” he agreed, shaking the offered hand. 

“You’re leaving soon, I suppose?” Rosamund said, letting go and stepping back.

“Yes,” Sherlock replied. 

“In that case, I’ll leave you to prepare. Thank you, Sherlock.” 

“And you,” Sherlock said, suddenly feeling a bit morose at his...friend?... _ friend’s  _ departure.

With that, Rosamund smiled one last time at him and turned away.

Sherlock watched as she melted into the shadows before turning and heading slowly towards his flat.

The sun had barely risen as Sherlock stepped out onto the apron of the local regional airport the next day. He adjusted the flimsy, neon-yellow safety vest as he made his way out to the little private jet standing ready at the edge of the apron.

“Good morning, Mr. Holmes,” the ground crew worker greeted him as he approached the stairs. “Your bag’s been loaded on already.”

Sherlock nodded in both greeting and gratitude as he climbed the stairs, shed his vest, and headed to his seat. He was alone today.

He sighed, remembering the events of the night before: of Rosamund, and dinner, and swings, and the chase, and the handshake.

For a moment he suddenly wished he’d done more than shake her hand.

Sherlock shook his head frantically and buckled his seatbelt. That was  _ over.  _ He was going home.

He sat in stony silence as a pilot came out to give him a security brief, then closed the cabin door with a final  _ thud  _ and left him alone with his thoughts.

Finally, the airplane began to taxi out towards the runway, and Sherlock looked out his window towards the mountains.

His mouth gaped in shock.

A familiar aircraft marshaller stood outside in an orange vest, auburn hair stirred up slightly in the breeze and greenish eyes sparkling with what Sherlock judged as a suppressed laugh. She smiled slightly as she began to signal to the pilots with high-visibility paddles. Sherlock did a little wave at her as the airplane began to move, and Rosamund tipped him a subtle wink.

Sherlock watched Rosamund breathlessly. So this was how she was bidding him farewell. He couldn’t help it and let out an undignified snort. Obviously she  _ hated  _ leaving him with the last word.

As the airplane turned onto the runway, held, and began to accelerate towards V 1 , Sherlock settled back into his seat with a smile and hoped that somehow, their paths would cross again.

* * *

 

_ Several years later _

Sherlock pulled away from the gravestone and sighed heavily. Rosamund... _ Mary... _ she had been brilliant.

But now she was dead.

He reached out shakily and traced the cold stone. 

_ In saving my life she conferred a value on it,  _ Sherlock had said to John.  _ It is a currency I do not know how to spend. _

How perfectly the dominoes fell when pushed, by the hand with such a price attached to it! Most likely the stolen card had put Lady Smallwood in contact with what he now knew was AGRA, which led to Tbilisi, which led to Rosamund’s journey to England and her meeting with and marriage to John and then her child and then…

And then her death.

The dominoes had fallen. And Rosamund had fallen, too.

Yes, Edmond Locard had been correct - every contact left a trace, and every interaction involved bringing and taking. Bringing and taking, bringing and taking. Everyone was always bringing and taking.

The little card that he had brought along with him, that she had taken, had truly had an effect. And what else did they say? That it was evidence that never forgot?

Sherlock closed his eyes. They’d never really talked about their meeting in that little boring town, but Sherlock knew that once she’d entered John’s life she was entering  _ his,  _ too, in a way, and he was glad for it. And now he was the godfather of her child, the child of two of his greatest friends.

He didn’t know squat about where to turn.

“Help me,” he whispered despite himself, tracing his fingers over the engraved name on the stone. “Please.”

“Well, fine then,” a voice said from behind him. “You helped me, after all.”

Sherlock turned around so quickly that he ended up sprawled against the headstone.

A pair of greenish eyes sparkled at him as he sat up and stared.

“What, you thought me an amateur? You thought me dead? I’d have thought better of you, Sherlock.”

He let out a little gasp as she smiled, crouched down, and folded him into her arms.


End file.
